Lavatory basin



FIG. 1 is a top view of a lavatory basin showing our new design;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a bottom view thereof; and

FIG. 6 is a right side elevational view thereof. 

The new and ornamental design for a lavatory basin, substantially as shown and described. 